The invention relates to a method for manufacturing an electrical heating device of the type generally known from WO 2007/071335 A1.
WO 2007/071335 A1 discloses electrical heating devices comprising a housing, which is produced from an extruded profile. The extruded profile comprises a plurality of tubes that are connected by one or two plates extending between each tube. Openings are cut into the plates. Fluid to be heated can flow through the openings and thereby absorb heat generated by heating resistors disposed in the tubes.
One advantage of such heating devices is that the heating resistors are protected by the tubes. Accidents resulting from inadvertent contact with the heating resistors are therefore practically impossible. In addition, the heating resistors are protected from the fluid to be heated. A disadvantage, however, is a high flow resistance of the heat dissipation plates between the tubes. Although this flow resistance can be reduced by increasing the number or the surface area of the openings, this increasingly diminishes the heat transfer.